Metallic reinforcement for concrete structures.



PATENTED MAR. 10, 19 38.

E. D. PITT & L. G. ROBINSON.v METALLIC REINFORCEMENT FOR CONCRETE STRUCTURES.

APPLICATION TILED DEO.10,1906. RENEWED JAN.3119-O8.

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' itEINFoRoE'MENT noncoiwcnErn STRUCTURES.

ngesneivl f To all whdm it m'aytoncem:

Be it known that we, ETHEL ERHT'DoTY fjPIT'r, of the city of Niagara Falls, iii'the' county of Welland, in the Province ofOritario,. tCanada,' and-LAFoREsT GEORGE ROBIN- .s0N of'th 'e city of Plattsburg, in the county of Clinton, fin'the State of New, York, United States of America have inven'te d cert ain new anduseful Improvements in Metallic Reinforceinents for Concrete Structures, of which the following is-thespecification.

Our invention relates to'improvements in metallic rg--intorcei'nen'ts' for concrete st-ructures,- and thtefo bject of..theinx ention is to devise reinforcement which maybe made of'comn ercial steel or other metal in which the section of the main bar'or member is 0011- v stant throughout its. length andnot weak -ened or injured by the attachment of the" 20, shearing member or members. I

' A further object-is to so Construct the shearing member, so that when the stress is exerted thereon itwill-tend to more securely jbind it imposition on the main member or '25 a v Further objects areto economize metal in the construction of the truss or reinforcement, to dispose the metal in convenient form throughout the length of the bar or main member as will be most efficient under all conditions of load, make the re-inforcemerit of such a width that it can be conveniently placedin thebeain andof such a depth as the load requires and to provide for the ready adjustability of, the shear or shear members as may be required to take up the 'shearstress. To these ends I have constrncted the main member of the truss for reinforcing concrete preferably of a steel bar 40 of suitable cross section and the shear member likewise of a steel strip or bar of suitable cross section in a double form connected to the main bar by a suitable. clip, the two portions of the shear member being twisted to '45 hold them and the clip in position on the main member and being disposed, -'so that they lie obliquely or in any suitable convenientrelati e position to the main bar.

Figure 1 is a perspective view of portion oi a truss constructed in accordance with my invention. Fig. 2, is a plan View.

a Vertical section. Fig. 4, is a detail of the a "clip show 11 in Figs. 1, 2 and 3 .Fig. 5, is a erspecti e View of a modification. Fig. 6,

1s a detail of the clip used in Fig. 5.

E'FHIELBER-HT-DOTY PI'iT; OF "nnteanitriiris. ONTARIO, CANADA, its, Kits .RO QNL F T Q EWYORK.

I j v j I Specifi eationpf Letters ifa tent'.v v Patented Marclr' lg, ji A plicationfiled December 10, mos, Serial N6. 357,227., Renewed January 31,1908. I I I been used as a sulxs titute toa' Y. w th its compressive str'efigt 1 complex and structural stri-ven to solve the most eco'f ohi brief term of popularity until at'pr taken care of by the proper placing of the Fig. 3, 1S

ther-{drawings like .lettiersfot ef indicate corresponding parts' iii e 'During severa l' years 1 s't one and steel-inbuildingcorrstr it I however, cannot bedependei tjpc Sllfi strength, wh ch is sin I'eason,steel has been used agent, totake up the tensilefst er structure. The internal "st tural ineinbersot an e'di ti ti agitate entice at manner of depositingthe steel in tl'iii i' diit-r .te tfi ilY- 7h tain etficient results fromtl i e llietiilte' whole; One after anothei sr H V ilirtiioiis been advanced, accepted esweetest other solut ons, which in t-iirir njo ll "'ent are mo're thantwenty S0llltl( common use, and inoreor less" itce iirst the steel employed to t? sile stresses was inordina-ry and placed judicially in t-encreienva much idea as to economy. 'lzhen as 't'gbin p tition grew keener there. can'ie a deiii-tiiidl 'i or greater. economyand efficiency. It was soon found that if the shear stresses .were well.

steel the strength ofthe unit would be greatly increased, hence many of. the systems developed were worked out with this end in view, but required a special treatment of the steel to give a special form to. the bar allowing of greater adhesion of the concrete to it. In another form the bars were rolled with wings and sheared on the line of connect-ion of the wings to the bar to give a diagonally placed; shear member. These special rol ed bars were expensive, are difficultto procure at times and in many respects are very unsatisfactory for general-use.

My invention is particularly designed to overcome the objections herebefore-experienced andprovide greater elasticity of application at all points and in all ways.

in referring to Figs. 1, 2, 3 and 4 A is the main or longitudinal member and B the stirrup or shear member, which is shown in these figures in a double form bent interme. diately to extend around the major portion of the main member A and passing through slot-s C in the'clip C T he two upper portions B ofthe member B are twisted at B a quarter turn or as may be desired at the point immediately where they emerge from the-slots C, thereby serving tocramp or lock the stirrup in position upon the bar, although not sufficiently so as to prevent longitudinal movement thereon for the purpose of adjustment.

The portions B are shown in the drawing placed with theirface's flatwise or on a plane obliquely to the lane of the top face of the main member or ar, and it will also be seen that the two portions B are disposed substantially parallel to each other. It will, however, be readily understood that thedisposition of theportions B of the stirrup may e disposed as may be most conducive to take up the shearing stress, this depending, ofcourse, upon the nature of the structure in which they are placed.

In Figs. 5 and 6 we show the clip C in U- shapefo'rm and also the stirrup itself and provided with slots C through which the stirrup B extends crosswise of the main member or bar lying close to it and the sides of the U-shape clip are designed to cramp the main bar or member. This cramping 1s effected'by the quarter. turn or other twist B given tothe lower endof the stirrup B immediately outside of the slots of the clip In these figures the portions B of the stirrup are disposed similarly to that in which the portionsB are disposed in Fig. 1, and like- Wise inthis construction the disposition of the portions B taking up the shearing stresses may be altered'to suitthe particular structure.

By-the use of a re-mforcement such as we describe both the tensile and shearing strains tip the clip and make it secu'relygrip' the bar and hold the shearing member from longitudinal displacement on the mam bar. in other Words the holding power of the connection between the shearing member and the main member is directly proportional to the intensity of the stress when embedded in the concrete. It will be, however, understood that the shearing member may be readily adjusted longitudinally on the main member or bar as the frictional grip upon the main member by the shearing member is such that it may be forced along by striking with a hammer the clip at the mint of connection to the bar or main mem er What we claim as our invention is.

In metallic re-inforcement for concrete structures the combination with the main member, of a flat shear member doubled around said main member and extending at right angles thereto, ia cross bar lyingon the main member and having two slots through which the two ends of the shear member extend sald shear member being twlsted and inclined at the points where it emerges fromthe slots of the cross bar.

V E'lilllhlilllilll l/OTY ll ll.

LAFOREST GEORGE ROBINSON. Witnesses B. BYD, J. H LL. 

